As shown in FIGS. 5A and 5B, a conventional ultrasonic diagnostic apparatus is configured so as to perform drive control of a two-dimensional array probe 1 formed by arranging a plurality of ultrasonic elements two-dimensionally so as to intermittently perform three-dimensional scanning of a target with the two-dimensional array probe. In an interval of three-dimensional scanning T3 performed intermittently, two-dimensional scanning T2 is performed at a scanning rate higher than the scanning rate at the three-dimensional scanning time and a three-dimensional image is formed based on a method obtained by the three-dimensional scanning and a two-dimensional image is formed based on a method obtained by the two-dimensional scanning (for example, refer to patent document 1).
Patent document 1: Japanese Patent Laid-Open No. 2000-139906 (paragraphs 0009 and 0010 and FIGS. 2 and 4)